Amorphous defect clusters of pure Si and type inversion in Si detectors

Abstract

Si detectors subjected to energetic particle bombardment are known to undergo a deleterious type inversion from $n$ type to $p$ type. The effect is due to defects that trap electrons but the identity of the main responsible traps remains unknown. Using a combination of classical molecular-dynamics simulations and large-scale density-functional theory calculations, we show that amorphous defect clusters formed under particle bombardment are strong acceptors of electrons and may as such well explain the phenomenon.